from datetime import datetime
import time

try:
    from workflowlib import requests
except:
    import requests

import json
import pandas as pd 



class PointReader:
    
    def __init__(
        self,
        point_ids: list,
        dt_begin : datetime,
        dt_end   : datetime,
        url      : str
    ) -> None:
    
        self.point_ids = point_ids
        self.dt_begin  = dt_begin
        self.dt_end    = dt_end
        self.url       = url
    
    def _read(self,dt_begin=None,dt_end=None) -> pd.DataFrame:
        
        dt_begin = self.dt_begin if dt_begin is None else dt_begin
        dt_begin = dt_begin.replace(second=0,microsecond=0)
        dt_end   = self.dt_end if dt_end is None else dt_end
        dt_end   = dt_end.replace(second=0,microsecond=0)
        
        if dt_begin > dt_end:
            raise Exception('开始时间晚于起始时间')
        
        ts_begin  = round(dt_begin.timestamp())
        ts_end    = round(dt_end.timestamp())
        
        post_data = {
            "point_ids": self.point_ids,
            "begin"    : ts_begin,
            "end"      : ts_end,
            "interval" : 1,
            "type"     : 3,
        }
        
        try:
            res       = requests.post(url=self.url, data=json.dumps(post_data))
            time.sleep(0.1)
            res_state = res.json()['state']
        except:
            print('post_data',post_data)
            print('url',self.url)
            print('res',res)
            print('json',res.json())
            raise Exception(res.json())
        
        if res_state != 0:
            print('post_data',post_data)
            raise Exception(res.json())
        
        point_df = []
        for point_info in res.json()['data']:
            point_id   = point_info['point_id']
            point_data = point_info['data']
            
            if (point_data is None) or (len(point_data) == 0):
                print('post_data',post_data)
                print('res.json',res.json())
                print('未获取到对应的点位数据, 检查时间是否正确')
                continue
            
            df = pd.DataFrame(point_data).rename(columns={'value':point_id}).set_index('ts')
            point_df.append(df)

        if len(point_df) == 0:
            print('post_data',post_data)
            print('res.json',res.json())
            print('所有点位的数据均未获取到, 需检查点位或接口')
            return None
        
        data       = pd.concat(point_df,axis=1)
        data.index = pd.to_datetime(data.index,unit='s',utc=True).tz_convert('Asia/Shanghai')
        data       = data.tz_localize(tz=None)
        
        return data

    def read_interval(self) -> pd.DataFrame:
        interval = pd.date_range(start=self.dt_begin, end=self.dt_end, freq='1D').to_pydatetime().tolist()
        interval += [self.dt_end]
        
        data = []
        for idx in range(len(interval)):
            if idx == len(interval)-1:
                continue
            start      = interval[idx]
            end        = interval[idx+1]
            finish_pct = round((idx+1)/(len(interval)-1) * 100,2)
            print(f'获取第{idx}段数据({finish_pct}%)，开始时间:{interval[idx]}，结束时间:{interval[idx+1]}')
            
            data.append( self._read(dt_begin=start,dt_end=end) )
        data = pd.concat(data,axis=0)
        data = data.loc[~data.index.duplicated(keep='last'),:].sort_index()
        
        return data 
    
    def read_int_interval(self,freq='H') -> pd.DataFrame:
        
        if freq == 'H':
            start = self.dt_begin.replace(minute=0)
            end   = self.dt_end.replace(minute=0)
        elif freq == 'D':
            start = self.dt_begin.replace(hour=0,minute=0)
            end   = self.dt_end.replace(hour=0,minute=0)
        
        start        = start.replace(second=0,microsecond=0)
        end          = end.replace(second=0,microsecond=0)
        int_interval = pd.date_range(start=start, end=end, freq=freq).to_pydatetime()
        
        if len(int_interval) == 0:
            raise Exception(f'在指定的日期范围下没有获取到对应的时间点(start:{start},end:{end},freq:{freq})')
        
        # data = [self._read(dt_begin=dt,dt_end=dt) for dt in int_interval]
        data = []
        for idx,dt in enumerate(int_interval):
            data.append(self._read(dt_begin=dt,dt_end=dt))
            finish_pct = round((idx+1)/(len(int_interval)) * 100,2)
            print(f'获取第{idx}段数据({finish_pct}%)，时间:{dt}')
            
        data = pd.concat(data,axis=0)
        data = data.loc[~data.index.duplicated(keep='last'),:].sort_index()
        
        return data